index.html

<!DOCTYPE html>
<html>
  <head>
    <!-- Required meta tags always come first -->
    <meta charset="utf-8" />
    <meta
      name="viewport"
      content="width=device-width, initial-scale=1, shrink-to-fit=no"
    />
    <meta http-equiv="x-ua-compatible" content="ie=edge" />

    <!-- Bootstrap CSS -->
    <link
      rel="stylesheet"
      href="node_modules/bootstrap/dist/css/bootstrap.min.css"
    />
  </head>

  <body>
    <h1>This is a Header</h1>
    <p>This is a paragraph</p>
    <p>This is a second paragraph</p>
    <!-- jQuery first, then Popper.js, then Bootstrap JS. -->
    <script src="node_modules/jquery/dist/jquery.slim.min.js"></script>
    <script src="node_modules/popper.js/dist/umd/popper.min.js"></script>
    <script src="node_modules/bootstrap/dist/js/bootstrap.min.js"></script>
  </body>
</html>